The real value is that we can use HTTPs for the communications, and that the site can mainly be…

The real value is that we can use HTTPs for the communications, and that the site can mainly be trusted to be real (if not, their certificate can be revoked, or not issued in the first place). The certificate is used in the secure handshake of data (using ECDHE-RSA), and where the digital certificate is used to validate that there is no "Eve-in-the-middle".